Control circuits for servomotors are known, see for example, German patent disclosure document DE-OS No. 2 350 958. That publication describes a control circuit including an electronic bridge circuit consisting of four semiconductor switches. The servo motor is connected as a lateral branch of the bridge while an input circuit determines the desired direction of rotation of the servomotor by rendering one or the other of the diagonally positioned branches of the bridge conducting. When the servo motor is to be stopped, all the semiconductor switches of the bridge circuit are blocked thereby making it impossible to perform a rapid electrical, i.e., dynamic, deceleration and stopping of the servomotor.
Another known system, described in the German disclosure document DE OS No. 2 640 792, describes a control system which shortcircuits the motor for the purpose of rapid deceleration. The short-circuiting is performed by a relay circuit because, as is stated in the publication, the expense of a purely electronic circuit would be too great.